bcroe wrote:I thought the same balancer fit all Olds V8s, weight differences were taken care
of in the crank weights. Bruce Roe
One would expect that. But if you look at the notes on the various supplier/vendor websites, they usually warn about rebalancing is required for the early 400 and 425 engine applications. If you look at the above picture you will see why. The Mondello literature also mentions this. It is interesting to see how some vendors offer it as a fit for the 425, some don’t offer it as a fit at all, and some offer it as a fit with a note that “a good harmonic balancer shop can rebalance it for you.” LOL. I called around for this type of work and could write a book about the responses I got. Everything from confusion, denial, to the “I don’t want to do it” price.
My engine is still stock, so it doesn’t have an engine specific counterweight requirement. Perhaps when I rebuild it one day, it will get a properly balanced rotating assembly.